#!/usr/bin/perl use warnings; use strict; use diagnostics; my $Dna1 = "AACAGCACGGCAACGCTGTGCCTTGGGCACCATGCAGTACCAAACGGAACGATAGTGAAAACAATCACGA\n"; while ($Dna1 =~ /(C[AG]G)/g) { my $endposition = pos($Dna1) + 1; print "Pattern C[AG]G matched $1 ending at $endposition\n"; }